Boilers for reducing temperature gradient and improving water circulation



July 6, 1965 H. GERBERT BOILERS FOR REDUCING TEMPERATURE GRADIENT AND IMPROVING WATER CIRCULATION Filed Jan. 28, 1963 10 van for: Zauz GezzmzT r an:

United States Patent 9 Claims. 61. 122--136) The present invention relates to boilers, particularly to tubular boilers, in which the fluid to be heated is conveyed by tubes through the combustion chamber.

In such boilers the water or other fluid to be heated is usually passed through metal tubes so arranged in the combustion chamber that flames and smoke heat the outer walls of the tubes thereby causing the water to circulate because of the resulting temperature gradient. These conventional boilers have the disadvantage that the water tubes are not arranged in the lowest part of the combustion chamber. Consequently, the ratio of the combustionchamber or flue diameter to the area of cold water to be heated is too small; the water velocity in the boiler is too low; and the flow-in and flow'away conditions near the cold-water inlet cause unfavorable distortion of the temperature gradient by formation of liquid layers having to control such circulation by the means provided in accordance with the invention.

Finally, it is an object of the invention to provide channels interconnecting the water jackets in such a way that an additional direction of water flow is obtained.

Among the features of this invention is a flared channel interconnecting the outer and the inner water jacket at a point close to the lowermost portions of the heating spaces in the jackets, the flared end of this channel communicating with the reflux or cold-water inlet.

Another" feature of the invention is an arrangement of upper and lower channels interconnecting the outer and inner jackets in such a manner that the total cross-sectional area or effective flow section of the upper channel or channels is at least twice as large as that of the lower channel or channels, thus increasing the velocity of the water flowing through the lower channel. As a result, a

. great suction eifect is produced whereby the cold water is removed from the lower boilerspace.

Still another feature of the invention is the arrangement of the reflux or cold-water inlet directly under the flared channel so as to increase the water circulation.

According to another feature of the invention, the upper and lower interconnecting channels are arranged in axially offset relation so as to obtain an additional direction of water flow which is inclined with respect to the vertical.

Further objects and advantages of the invention will become readily apparent from the following description in conjunction with the appended claims and drawings in which FIG. 1 is a sectional elevational view of the boiler in accordance with the present invention;

FIG. 2 is a cross-section of the boiler in FIG. 1, along line II;

FIG. 3 is a sectional view of a boiler in accordance with this invention, differing from the embodiment in FIG. 1 in that the inlet and lower connecting channel are 3,192,906 Patented July 6,1965

arranged at the front end of the combustion chamber, while the outlet of the outer water jacket is provided at the rear end of the'combustion chamber; and

FIG. 4 is a cross-section of the boiler of FIG. 3, along line HIIII. i

As is seen in FIG. 1, the boiler according to the invention has two double water jackets 9 and 10 which are of coaxial cylindrical shape, the inner jacket 10 enclosing the combustion chamber 11. A reflux-water inlet 1 is provided at the lowermost portion 2 of the outer jacket 9. Arranged directly above and coaxial with the orifice of the inlet 1 is the orifice of a channel 7 interconnecting the outer and inner cylinder jackets 9, 10. The lower end of channel 7 has a flared-out portion 3 which may be constructed of special tube sections or deflectors (not shown). Two upper channels 5, 6 are provided for interconnecting jackets 9, 10 at the upper side.

The water is heated by a burner (not shown) which can be inserted into an aperture 12 provided for this purpose. The flue gases may escape through an annular chamber 13 between the jackets 9, 10 and an exhaust duct 14. Heated water is withdrawn through an outlet 18.

Basically, the boiler shown in FIG. 3 is of the same type as the boiler in FIG. 1. In this embodiment, however, the inlet 1 and the outlet 18 are respectively arranged at the front and the rear ends of the boiler. Similarly, the lower connecting channel 7 and the upper connecting channel 6 are respectively arranged at the front and the rear ends of the boiler. Moreover, in the boiler shown in FIG. 3 only one upper connecting channel 6 is provided, whereas in FIG. 1 two such channels, 5, 6, are

shown. In either case, however, the operation is the same.

The cold reflux water enters the boiler through inlet 1 and normally covers the lowermost jacket portion-2. As soon as the water is heated, it flows upwards through channels 7, 5, 6 as indicated by the arrows in FIGS. 1 through 4. Owing to the dimensions of the upper chan- ''nel or channels where the effective flow section of the channel or channels is at least twice as large as that of the lower channel, a strong'thermal suction is generated. This suction coacts with the flared-out portion 3 of lower channel 7 thereby removing by suction the cold water from the boiler bottom.

Due to the axially offset relationship of the upper and lower connecting channels, 5, 6, 7 the heated water rises not only vertically but also in an additional direction indined with respect to the vertical. This is indicated by arrows 15, 16 in FIG. 1 and arrow 17 in FIG. 3. As a result, the heated surfacesare cooled uniformly.

It will be understood that the means, devices, a and arrangements provided by the present invention, and the combination thereof, may be modified in various ways without departing from the spirit of the invention. Hence, the appended claims are intended to cover such modifications and variations as fall within the scope of the invention.

What is intended to be secured by Letters Patent is:

1. In a boiler, in combination:

(a) an outer jacket means including spaced inner and outer walls enclosing a first heating space of annular cross section about a horizontally extending axis,

(1) said inner wall enclosing a central space adjacent said axis, and

(2) said heating space being radially separated from said central space by said inner wall;

(b) an inner jacket means in said central space,

(1) said inner jacket means including spaced inner and outer walls enclosing a second heating space of annular cross section about said axis,

(2) the inner wall of said inner jacket means forming a combustion chamber adjacent said axis,

first heating space upwardly spaced from said axis,

(1) said first conduit means extending upward from said first toward said second heating space, and said second conduit means extending upward from said second toward said first heating space,

(2) said first conduit means including at least one conduit connecting said heating spaces, and flaring in a direction from said second toward said first heating space,

(3) the effective flow section of said second conduit means being substantially greater than the effective flow section of said first conduit means; and

(f) outlet means for Withdrawing a heated fluid from one of said heating spaces.

2. In a boiler as set forth in claim 1, said inlet means and said one conduit having respective coaxial orifices in said first heating space, said orifices being vertically spaced from each other.

3. In a boiler as set forth in claim 1, said inner and outer jacket means being substantially cylindrical about said horizontally extending axis.

4. In a boiler as set forth in claim 1, said inner and outer jacket means being radially spaced from each other and defining therebetween a channel of annular cross section communicating with said combustion chamber. 5. In a boiler as set forth in claim 1, said first portions of said heating spaces being the respective lowermost portions of said spaces, and said second portions of said heating spaces being the respective uppermost portions of heating spaces.

6. In a boiler as set forth in claim 1, said outlet means directly communicating with a portion of said first heating space remote from said first portion thereof.

7. In a boiler as set forth in claim 6, said remote portion of said first heating space being upwardly spaced from said first portion.

8. In a boiler as set forth in claim 1, said second conduit means being axially offset with respect to said first conduit means.

9. In a boiler, in combination:

(a) an outer substantiallycylindrical jacket including spaced inner and outer walls enclosing a first heating space of annular cross section,

(1) said jacket having a horizontally extending axis,

(2) said inner wall enclosing a central space adjacent said axis, and

(3) said heating space being radially separated from said central space by said inner wall;

(b) an inner jacket in said central space,

(1) said inner jacket being substantially cylindrical about said axis and including an inner and an outer wall enclosing a second heating space of annular cross section,

(2) the inner wall of said second jacket forming a combustion chamber adjacent said axis, and radially separating said combustion chamber from said second heating space,

(3) said jackets being radially spaced to define ,therebetween a channel of annular cross section communicating with said chamber;

(c) inlet means for feeding a fluid to be heated to the lowermost portion of said first heating space;

(d) lower conduit means connecting said lowermost portionof said first heating space with the lowermost portion of said second heating space;

(e) upper conduit means axially offset from said lower conduit means and connecting the uppermost portion of said second heating space with the uppermost portion of said first heating space,

(1) said lower conduit means extending upward from said first heating space toward said second heating space, and said upper conduit means extending upward from said second heating space toward said first heating space,

(2) said lower conduit means including at least one conduit connecting said heating spaces and flaring in a downward direction,

(3) the effective flow section of said upper conduit means being at least twice the efliective flow section of said lower conduit means,

(4) said inlet means and said one conduit having respective coaxial orifices in said first heating space, said orifices being vertically spaced from each other; and

(f) outlet means communicating with said uppermost portion of said heating space.

References Cited by the Examiner UNITED STATES PATENTS 1,589,162 6/26 Hillyer 122-406 2,531,459 11/50 Marshall 122136 FOREIGN PATENTS 1,215,040 11/59 France.

PERCY L. PATRICK, Primary Examiner.

FREDERICK L. MATTESON, 1a., KENNETH W.

SPRAGUE, Examiners. 

1. IN A BOILER, IN COMBINATION: (A) AN OUTER JACKET MEANS INCLUDING SPACED INNER AND OUTER WALLS ENCLOSING A FIRST HEATING SPACE OF ANNULAR CROSS SECTION ABOUT A HORIZONTALLY EXTENDING AXIS, (1) SAID INNER WALL ENCLOSING A CENTRAL SPACE ADJACENT SAID AXIS, AND (2) SAID HEATING SPACE BEING RADIALLY SEPARATED FROM SAID CENTRAL SPACE BY SAID INNER WALL; (B) AN INNER JACKET MEANS IN SAID CENTRAL SPACE, (1) SAID INNER JACKET MEANS INCLUDING SPACED INNER AND OUTER WALLS ENCLOSING A SECOND HEATING SPACE OF ANNULAR CROSS SECTION ABOUT SAID AXIS, (2) THE INNER WALL OF SAID INNER JACKET MEANS FORMING A COMBUSTION CHAMBER ADJACENT SAID AXIS, AND RADIALLY SEPARATING SAID SECOND HEATING SPACE FROM SAID COMBUSTION CHAMBEER; (C) INLET MEANS FOR FEEDING A FLUID TO BE HEATED TO A FIRST PORTION OF SAID FIRST HEATING SPACE DOWNWARDLY SPACED FROM SAID AXIS; (D) FIRST CONDUIT MEANS CONNECTING SAID FIRST PORTION OF SAID FIRST HEATING SPACE WITH A FIRST PORTION OF SAID SECOND HEATING SPACE; (E) SECOND CONDUIT MEANS CONNECTING A SECOND PORTION OF SAID SECOND HEATING SPACE UPWARDLY SPACED FROM SAID FIRST PORTION THEREOF WITH A SECOND PORTION OF SAID FIRST HEATING SPACE UPWARDLY SPACED FROM SAID AXIS, (1) SAID FIRST CONDUIT MEANS EXTENDING UPWARD FROM SAID FIRST TOWARD SAID SECOND HEATING SPACE, AND SAID SECOND CONDUIT MEANS EXTENDING UPWARD FROM SAID SECOND TOWARD SAID FIRST HEATING SPACE, (2) SAID FIRST CONDUIT MEANS INCLUDING AT LEAST ONE CONDUIT CONNECTING SAID HEATING SPACES AND FLARING IN A DIRECTION FROM SAID SECOND TOWARD SAID FIRST HEATING SPACE, (3) THE EFFECTIVE FLOW SECTION OF SAID SECOND CONDUIT MEANS BEING SUBSTANTIALLY GREATER THAN THE EFFECTIVE FLOW SECTION OF SAID FIRST CONDUIT MEANS; AND (F) OUTLET MEANS FOR WITHDRAWING A HEATED FLUID FROM ONE OF SAID HEATING SPACES. 